A power inductor used for a power supply circuit is required to be small, low-loss, and capable of responding to high current. In order to respond to these demands, there have been developed inductors employing, as a magnetic material of such inductors, a composite magnetic material such as metal magnetic powder having high saturation magnetic flux density (e.g., Japanese Patent No. 4714779). One advantage of the inductors employing a composite magnetic material is high direct-current superimposed allowable current. However, in order to reduce a size of the component while maintaining self-inductance L, it is necessary that a part made of the composite magnetic material to be thin. In this case, a power inductor having a structure in which a coil is embedded in a composite magnetic material is manufactured one by one, and accordingly poses a problem that separation of the composite magnetic material easily occurs at a portion where the composite magnetic material is thin, especially on a side of the component, resulting in a poor yield ratio and difficulty in size reduction.
There is another conventional approach of molding a core using granulated powder, placing a coil in the core, and performing compression molding one by one. However, with this conventional approach, inductors cannot be manufactured unless a core is molded using granulated powder. In particular, as a side wall is required to be made thin to reduce a size, it is not possible to manufacture a molding mold for molding a core, and thus there is a problem that size reduction is difficult.